And regarding the rest, nothing can be done to recover it. As per the terms of service of PUBG MOBILE, every player is acknowledged and accepted upon their account creation, that the owner is solely responsible for securing their account. If any changes were made to the account, for example changes of flag/server/username, in-game currencies spent or anything else, whether it was by the owner or someone else that compromised your game account, all these changes cannot be reverted.